Amazon RDS for Oracle now supports major version upgrade from 11g to 12c.

To upgrade your existing RDS for Oracle instances running 11g (11.2.0.4) to 12c(12.1.0.2.v5) with just a few clicks from "Modify DB Instance Wizard" in the AWS Management Console, select the appropriate DB Engine version (12.1.0.2.v5). To learn about the enhancements and new features included in 12.1.0.2.v5, please refer to our documentation on Oracle versions.

If you are using Oracle Standard Edition or Oracle Standard Edition One on your instances running 12.1.0.1 or 11.2.0.4, the supported version for upgrade to 12.1.0.2 is Standard Edition Two. Please Refer to our documentation on Oracle Standard Edition Two upgrade paths for more details.

To upgrade your instances running 11.2.0.2 or 11.2.0.3, you need to first upgrade them to 11.2.0.4 followed by the upgrade to 12.1.0.2 mentioned above. To learn about the upgrade paths supported, please refer to our documentation on upgrade paths supported.